Industrial buildings often have skylights to provide natural lighting and to conserve energy. For buildings with metal roof systems, skylights or “light panels” may be provided in the roof system. The light panels typically have a clear or translucent sheet material formed into a shape similar to the shape of the structural metal panels of the roof, and metal sides for seaming into a standing seam type metal roof system. The light panels are lapped and sealed to the metal roof panels to provide weather-tight joints. An example of such a panel is shown in FIG. 1.
Because metal roofs typically are insulated underneath with blanket or rigid board insulation, sometimes insulation trim-flashing also is provided to terminate the insulation around the light panel opening. This allows sunlight to come into the building through the light panel.
Current light panels for metal roofing offer no permanent fall protection for people who walk on them. Usually, the light-weight, clear/translucent material of the light panels is, when new, strong enough to support the weight of a typical person and/or light equipment, or the impact from falls or dropped objects. However, as the material ages, it weakens and may lose the ability to support the design weights and impacts. Additionally, years of dirt and or debris may cover the light panel and make it hard for people on the roof to distinguish the light panels from adjacent metal roof panels, thereby increasing the risk of the light panel being stepped on. And in case of fire, the material may melt or weaken, posing a risk to a roof-borne firefighters.
Building authorities have attempted to resolve these safety issues by requiring that new building roofs have skylights installed on a roof curb, thereby elevating the light panel above the plane of the roof, and/or that security bar systems (FIG. 2) be installed over the light panel.
Both of these approaches make it easier to know where the light panels are on a roof, and both deter people from walking or standing on them. However, the additional material and labor required to implement these safety features on each of the many light panels of a large building are great.
Complicating the growing need for safer skylights that have inherent structural strength to avoid personnel or equipment fall-throughs, building codes are increasing the amount of roof area that is permitted or required to transmit light.
Thus, what is needed is a roof panel that maximizes light transmission while providing a sufficiently strong structure over the years, even in case of fire, to prevent people or equipment from falling through it.